In this study, the general partial differential equation of unsteady groundwater flow through non-homogeneous and anisotropic aquifer was solved by the fully implicit finite difference method with control volume approach. The calibration of permeability and storage coefficients as model parameters was performed by a transformation technique and application of Powell's non-linear optimization me...

The aim of lot sizing problems is to determine the periods where production takes place and the quantities to be produced in order to satisfy the customer demand while minimizing the total cost. Due to its importance on the efficiency of the production and inventory systems, Lot sizing problems are one of the most challenging production planning problems and have been studied for many years wit...

This paper describes the design of a forecasting framework to predict disruptive innovations. First, the nature and characteristics of disruptive innovation are presented, as well as the conditions that enable such a phenomenon. Individual factors that feed into disruptive innovations are identified, as well as formulae to allocate quantifiable measurement to these factors. Suitable principles ...

environmental impact assessment (eia) has led to the dominance of planners on the natural environment of the regions, providing the possibility of continuously monitoring and controlling the status quo by management staff. in this regard, a new semi-quantitative model is presented for the eia of the eastern alborz coal mining complex using the matrix method, and determining the corresponding im...

a r t i c l e i n f o We explore the sectoral and aggregate implications of some endogeneization rules (i.e. on value-added and final demand) which have been common in the extended demand-driven Leontief model and have been recently proposed in the supply-driven Ghosh model. Extended linear models are refinements that aim at endowing the linear models with additional general equilibrium feedbac...

introduction accurate estimation of the absorbed dose in radiosensitive organs, located away from the target volume during radiotherapy, is one of the main reasons for the development of reference phantoms. the international commission on radiological protection (icrp) reference phantoms can provide a more realistic view of the human anatomy in comparison with the previously used mathematical p...

In this paper, a mathematical method is proposed to formulate a generalized ordering problem. This model is formed as a linear optimization model in which some variables are binary. The constraints of the problem have been analyzed with the emphasis on the assessment of their importance in the formulation. On the one hand, these constraints enforce conditions on an arbitrary subgraph and then g...

background: treatment of ionizing radiation combined with chemical agents can enhance the inactivation of cells. the aim of this study was to determine the parameters involved in the inhibition of cell recovery. materials and methods: a mathematical model describing the process of recovery as a decrease in the effective radiation dose was used. the model includes two parameters, recovery consta...

the objective of this article is to analyze the data collected by the depart­ment of environmental health about the susceptibility of anopheles stephensi in the minab shahrestan to d.d.t. from 1957 to 1968, in order to: determine a mathematical model for the changes in l.d.50 by time and estimate the trend of l.d.50, for the future years. by plotting the changes in the resistance of the mosquit...